Dwgs_IFP_TCLF_CD_Unit_2_Landfill_Partial_Closure.pdf

PDF 11 MB Posted Oct 13, 2026

Attached to: CLASS 2 LANDFILL PARTIAL CLOSURE
Solicitation number: RFP #27027
Issued by: Greenville County, South Carolina

About this file

Written by GovTribe AI · Oct 26, 2026

This document is a set of contract drawings for the Twin Chimneys Landfill Partial Closure civil project located in Greenville County, South Carolina, prepared by HDR Engineering, Inc. of the Carolinas. The project involves the partial closure construction of Class 2 Unit 2 at the landfill, requiring approximately 301,000 cubic yards of excavation and 120,000 cubic yards of structural fill. The scope of work includes stormwater pond construction, subgrade preparation, perimeter berm structural fill, stone access road installation, and erosion control measures consisting of silt fence, erosion control blankets, and seeding. The drawings are issued for proposals as of October 8, 2026, and include an overall site plan, phase-by-phase grading plans (Phases 1, 2, and 3), technical details, and a skimmer basin specification. The contractor's primary site access is via the main landfill entrance at the scalehouse. The County seeks project substantial completion within 210 calendar days, with the soil borrow area located within the Unit 2 Landfill footprint.

The drawings specify detailed erosion and stormwater control requirements in accordance with the Greenville County Stormwater Design Manual Chapter 8, with particular emphasis on maintaining all erosion control measures to minimize sediment transfer. Key specifications include silt fence installation, reinforced silt fence, rock outlets, and gabion baskets for perimeter protection. Phase 1 includes north grading and east perimeter berm construction with cut/fill data of 108,173 cubic yards cut and 31,608 cubic yards fill (net 76,565 cubic yards). Phase 2 focuses on skimmer basin and associated road construction with 269 cubic yards cut and 10,629 cubic yards fill (net 10,360 cubic yards). Phase 3 encompasses top grading, perimeter road construction, and south/west stormwater channel installation with 192,364 cubic yards cut and 69,449 cubic yards fill (net 122,915 cubic yards). The total denuded area is approximately 35 acres of a 1,140.92-acre site spanning two parcels. The contractor is responsible for security of all tools, materials, and equipment, protection of existing wells, structures, utilities, and maintenance of all erosion and sediment control structures throughout the project duration.

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Other files

File	Type	Posted
CLASS_2_LANDFILL_PARTIAL_CLOSURE.pdf	PDF	Oct 23, 2026
Specs_IFP_TCLF_CD_Unit_2_Landfill_Partial_Closure.pdf	PDF	Oct 13, 2026
COG_Sub_W9_.pdf	PDF	Oct 12, 2026
Sample_Services_Agreement.pdf	PDF	Oct 12, 2026

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Twin Chimneys Landfill

Partial Closure Civil

Project No.

11075 Augusta Road

C o n t r a c t D r a w i n g s F o r

10174879

October 2026

I N D E X O F D R A W I N G S

GENERAL

21G-00 COVER SHEET

21G-01 OVERALL SITE PLAN

CIVIL

21C-01 OVERALL GRADING PLAN

21C-02 PHASE 1 GRADING PLAN

21C-03 PHASE 2 GRADING PLAN

21C-04 PHASE 3 GRADING PLAN

21C-05 DETAILS

21C-06 SKIMMER BASIN

Issued for Proposals

Class 2 Unit 2

Greenville County, South Carolina

HDR Engineering, Inc.

of the Carolinas 440 S. Church St., Suite 1200 Charlotte, NC 28202-2075 704.338.6700

10/08/26

0 82

0 74

750 740

0 78

740 745 75

740 73 5 73

0 72 5 72

0 71

660 660

5 76

715 720 725

735 730

725 720

760755

800 805

5 79

0 77

C&D A

CCES

ROAD

73074

75076

740750 760770780790

73073074074074 0750760770

710710710

770 78

0740 750 760 77

0 780

70071

074075

C L

D I T C H

C/ L

C/L

DITC

C/L

TCH

DITCH

C/L DI

TCH

DITCH

DIT

DITCH

DIT

C/L DITCH

C/L DI

TCH

C/L D

ITCH

C/L D

ITCH

C/L DI

TCH

DITCH

D I T C H

C/ L

DITCH

DIT

DITC

DIT

DITC

C/ L

705710715720725

730 73

74575075575575 575575

5 760760 765765 770770

70571 071572072573073574074575075

81081

780 82

73573573574

077578078

725725725 7307357407

5 77

770775780 785790795

800805810815820

695700705710715

680680

685690

0 86

0 76

0740750

760770780790800810

UNIT 2

C&D

CELL 1

CELL 2

FUTURE

UNIT 7

FUTURE

UNIT 5

CELL 3

CELL 4 CELL 5

ACTIVE

UNIT 4 MSW

CLAY

STOCKPILE

SEDIMENT

BASIN B

SEDIMENT

BASIN C

E-WASTE

METALS

PAD

YARD

WASTE

PAD

SEDIMENT

BASIN A

ROCK

STOCKPILE

17.0 ACRES

8.6 ACRES

COMPOST AREA

8.5 ACRES

10.3 ACRES

SOIL STOCKPILE

8.6 ACRES

UNIT 1 MSW

G W -3

-0

-1

-1 2 1-

-1

-1 5 1-

-1

-2

G W -3

G W -3 1G W -3

G W -2

G W -1

C S -1

C S -2

UGE

UGEUGE

UGE

OHW

LEACHATE

VAULT #1

36"RCP

INV:725.45

M P

INV:728.84

INV:730.90INV:733.21

INV:734.45

x 724.39 TP x 724.90 TP x 7

.0 8 T

P x 7

.4 9 T

TP 724.29 x

TP 722.02 x

TP 719.23 x

TP 717.04 x

OUTPARCEL

MM-1

MM-2

MM-3

MM-4

MM-5 MM-6

MM-7

MM-28MM-29

MM-30

MM-31

MM-32

MM-33

MW-4

MW-5

OW-115

MW-72

MW-48

MW-71

MW-47

MW-46

MW-45

MW-70

MW-30

MW-31

MW-32

MW-33

MW-37

MW-38

MW-39

OW-107

OW-108

MW-29

MW-28

MW-27

MW-26

MW-25

MW-66

MW-67

OW-113

OW-114

MW-61

MW-62

MW-24

MW-63

MW-64

MW-65

OW-103

MW-105

MW-13

MW-14

OW-104-R1

M W

-1

7 MW-18

M W

-1

OW-104

OW-105

MW-1

MW-2

MW-3

OW-102

OW-110

OW-109 MW-52

MW-6

MW-7

MW-51

MW-41

MW-12

MW-8

MW-50

MW-11

MW-10

MW-9

OW-101

MW-20

PZ-13s PZ-13d

PZ-44

PZ-7s

PZ-50

PZ-2d PZ-2s

PZ-4a

PZ-76

PZ-6d

PZ-53

PZ-54

PZ-56PZ-6s

PZ-5da PZ-5d

PZ-77

PZ-14

PZ-43

PZ-19

PZ-52s PZ-52d

PZ-7s

PZ-4

PZ-39s PZ-39d

PZ-26d PZ-26s

PZ-23d PZ-23s

PZ-75

PZ-51

PZ-10ra

PZ-41

PZ-57s

PZ-57d

PZ-78

PZ-73

PZ-30

PZ-25 PZ-25d

PZ-20

PZ-64

PZ-29

PZ-79

PZ-55

PZ-67

PZ-66s PZ-66d

PZ-12

PZ-74

PZ-65

PZ-9s

PZ-35d

PZ-35

PZ-62s PZ-62d

PZ-28

PZ-40

PZ-48

OW-105-R1

MW-10R

MW-21

MW-23

MW-22

MW-42

MW-43

MW-44

MW-49

MW-25

6 7 8

OVERALL SITE PLAN

21G-01.dwg

1" = 300' 21G-01

GENERAL NOTES:

1. EXISTING TOPOGRAPHY FROM TWO SEPARATE SURVEYS,FREELAND

& ASSOCIATES AERIAL SURVEY DATED JULY 15, 2021 AND DRONE

SURVEY IN UNIT 1,2 AND 4 AREA BY RP &ASSOCIATES DATED JULY

09, 2025.

2. CONTRACTOR'S PRIMARY ACCESS TO THE SITE SHALL BE VIA THE

MAIN ENTRANCE AT THE LANDFILL SCALEHOUSE.

3. CONTRACTOR RESPONSIBLE FOR SECURITY OF ALL TOOLS,

MATERIALS AND EQUIPMENT LEFT ON SITE. CONTRACTOR TO

SECURE ACCESS POINTS TO THE WORK SITE AS NECESSARY.

4. THE CONTRACTOR SHALL PROTECT ALL EXISTING WELLS,

STRUCTURES AND UTILITIES. ANY WELLS, STRUCTURES OR

UTILITIES THAT ARE DAMAGED SHALL BE REPLACED OR REPAIRED

(AS DIRECTED BY OWNER).

5. EROSION AND STORMWATER CONTROL MEASURES ARE INSTALLED

AND OPERATIONAL FOR THE DESIGNATED WORK AREAS.

CONTRACTOR TO MAINTAIN AND PROTECT THE STRUCTURES FROM

DAMAGE.

6. SITE BENCHMARK CONTROL IS LOCATED NEAR THE CELLULAR

TOWER.

CONSTRUCTION AREA

BORINGS (SB & B)

METHANE MONITORING (MM)

PIEZOMETER (PZ)

MONITORING AND OBSERVATION

WELL (MW,OW)

PROPOSED EXISTING ABANDONED

MW-P

MM-P

LEGEND

EXISTING 2021 & 2025 MAJOR CONTOURS

EXISTING 2021 & 2025 MINOR CONTOURS

WETLANDS

UNIT AND CELL BASELINES

PROPERTY LINE

EXISTING TREELINE

PZ-# PZ-#

B-#B-#

MM-#

MW-A

SEDIMENT

BASIN #T2

SEDIMENT

BASIN #T5

SEDIMENT

BASIN #T3

SEDIMENT BASIN #9

WETLANDS

SEDIMENT BASIN #10

DI #9

LEACHATE

TANKS

SCALE

HOUSE

ADMINISTRATION

BUILDING

EDUCATION

BUILDING

CELLULAR

TOWER

SEDIMENT

TRAP A

SEDIMENT

BASIN #T4

EXISTING CONSTRUCTION ENTRANCE

AUGUSTA RD

BRIDGE ROAD

SEDIMENT BASIN #11

100 YEAR FLOODPLAIN

LEACHATE

EVAPORATOR

CONCRETE

MONUMENT

N 987685.471 E 1604817.497

EL. 809.25

STOCKPILE ACCESS ROAD

(SEE SHEET 12C-03)

TEMPORARY

SEDIMENT BASIN A

LIMITS OF SURVEY

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

MM-28

MM-32

MM-33

MW-52

MW-51

MW-41

MW-8

MW-50

PZ-7s

PZ-19

PZ-39s

PZ-39d

PZ-26d PZ-26s

PZ-28

PZ-40

PZ-48

MW-42

MW-43

MW-44

MW-49

SF SF

SF SF SF

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

OVERALL GRADING PLAN

21C-01.dwg

1" = 100' 21C-01

LEGEND

EXISTING 2025 MAJOR CONTOURS

EXISTING 2025 MINOR CONTOURS

WETLANDS

UNIT AND CELL BASELINES

PROPERTY LINE

EXISTING TREELINE

PROPOSED MAJOR CONTOURS

PROPOSED MINOR CONTOURS

SFSFSFSF SILT FENCE

REINFORCED SILT

FENCE

SILT FENCE ROCK

OUTLET

GABION BASKETS

PERIMETER ROAD

21C-05

GENERAL CONSTRUCTION SEQUENCE:

1. ESTABLISH LIMITS OF CONSTRUCTION.

2. PERFORM INITIAL SURVEY OF THE CONSTRUCTION AREA TO

ESTABLISH BASIS FOR PAY QUANTITIES.

3. INSTALL SILT FENCE.

4. BEGIN PHASE 1 OF CONSTRUCTION. PHASE 1 INCLUDES

GRADING IN NORTH, CONSTRUCTION OF EAST SECTION OF

PERIMETER BERM AND STORMWATER CHANNELS AS SHOWN ON

DRAWING 21C-02.

5. AFTER COMPLETION OF PHASE 1 BEGIN THE PHASE 2

CONSTRUCTION. PHASE 2 INCLUDES CONSTRUCTION OF

SKIMMER BASIN, GRADING AND ROAD AROUND THE SKIMMER

BASIN AS SHOWN ON DRAWING 21C-03.

6. AFTER COMPLETION OF PHASE 2 BEGIN THE PHASE 3

CONSTRUCTION. PHASE 3 INCLUDES GRADING ON TOP,

CONSTRUCTION OF PERIMETER ROAD AND STORMWATER

CHANNEL ON SOUTH AND WEST AS SHOWN ON DRAWING 21C-04.

7. INSTALL THE PERIMETER ROAD GEOTEXTILE AND STONE.

8. PERFORM SEEDING OF THE EXTERIOR AND INTERIOR SLOPES.

9. UPON COMPLETION OF GRADING PERFORM ASBUILT

SURVEY OF THE CONSTRUCTION AREA AND THE

STOCKPILE. SURVEYS WILL BE USED FOR FINAL PAYMENT.

BORINGS (SB & B)

METHANE MONITORING (MM)

PIEZOMETER (PZ)

MONITORING AND

OBSERVATION WELL (MW,OW)

PROPOSED EXISTING ABANDONED

MW-P

MM-P

PZ-#

B-#

PZ-#

B-#

MM-#

MW-A

MW-51

MW-41

MW-50

PZ-7s

PZ-39s

PZ-39d

PZ-26d PZ-26s

PZ-51

PZ-57s

57d

PZ-40

PZ-48

MW-42

MW-43

MW-44

MW-49

SF SF

SF SF SF

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

PHASE 1

GRADING PLAN

21C-02.dwg

1" = 100' 21C-02

LEGEND

EXISTING 2025 MAJOR CONTOURS

EXISTING 2025 MINOR CONTOURS

WETLANDS

UNIT AND CELL BASELINES

PROPERTY LINE

EXISTING TREELINE

PROPOSED MAJOR CONTOURS

PROPOSED MINOR CONTOURS

CUT/FILL DATA

CUT (CY) 108,173

FILL (CY) 31,608

NET (CY) 76,565

SFSFSFSF SILT FENCE

PERIMETER ROAD

21C-05

BORINGS (SB & B)

METHANE MONITORING (MM)

PIEZOMETER (PZ)

MONITORING AND OBSERVATION

WELL (MW,OW)

PROPOSED EXISTING ABANDONED

MW-P

MM-P

PZ-#

B-#

PZ-#

B-#

MM-#

MW-A

MW-8

MW-50

PZ-7s

PZ-39s

PZ-39d

PZ-26d PZ-26s

PZ-51

PZ-57s

PZ-40

PZ-48

MW-42

MW-43

MW-44

MW-49

SF SF

SF SF SF

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

PHASE 2

GRADING PLAN

21C-03.dwg

1" = 100' 21C-03

LEGEND

EXISTING 2025 MAJOR CONTOURS

EXISTING 2025 MINOR CONTOURS

WETLANDS

UNIT AND CELL BASELINES

PROPERTY LINE

EXISTING TREELINE

PROPOSED MAJOR CONTOURS

PROPOSED MINOR CONTOURS

CUT/FILL DATA

CUT (CY) 269

FILL (CY) 10,629

NET (CY) 10,360

SEDIMENT BASIN

EMERGENCY SPILLWAY

SFSFSFSF SILT FENCE

21C-06

BORINGS (SB & B)

METHANE MONITORING (MM)

PIEZOMETER (PZ)

MONITORING AND OBSERVATION

WELL (MW,OW)

PROPOSED EXISTING ABANDONED

MW-P

MM-P

PZ-#

B-#

PZ-#

B-#

MM-#

MW-A

POROUS BAFFLES 5

21C-06

MW-8

MW-50

PZ-7s

PZ-39s

PZ-39d

PZ-26d PZ-26s

PZ-51

PZ-57s

PZ-40

PZ-48

MW-42

MW-43

MW-44

MW-49

SF SF

SF SF SF

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

PHASE 3

GRADING PLAN

21C-04.dwg

1" = 100' 21C-04

LEGEND

EXISTING 2025 MAJOR CONTOURS

EXISTING 2025 MINOR CONTOURS

WETLANDS

UNIT AND CELL BASELINES

PROPERTY LINE

EXISTING TREELINE

PROPOSED MAJOR CONTOURS

PROPOSED MINOR CONTOURS

CUT/FILL DATA

CUT (CY) 192,364

FILL (CY) 69,449

NET (CY) 122,915

SFSFSFSF SILT FENCE

GABION BASKETS

PERIMETER ROAD

21C-05

BORINGS (SB & B)

METHANE MONITORING (MM)

PIEZOMETER (PZ)

MONITORING AND OBSERVATION

WELL (MW,OW)

PROPOSED EXISTING ABANDONED

MW-P

MM-P

MW-A

B-#

PZ-#

MM-#

B-#

PZ-#

SUBGRADE

1/8"/FT. 1/8"/FT.

10.0' 4.0' 2.0' 4.0' 30.0' VARIES 12.0'

12.0'

MIN

24.0'

2 1

PERIMETER DITCH

L PERIMETER ROAD

EXTERIOR

CHANNEL

PERIMETER

BERM

ACCESS

ROAD

LANDFILL

WOVEN

GEOTEXTILE

12" STONE

EROSION

CONTROL

BLANKET

EROSION

CONTROL

BLANKET

12.0'

EROSION

CONTROL

BLANKET

SILT FENCE ROCK OUTLET

South Carolina Department of Health and Environmental Control

DATE

MEDIAN 8" DIA.

RIP-RAP

1'-0"1'-0"

3'-0" MIN.

30"

TOP OF FENCE

AASHTO #57 STONE

FACE ON UPSTREAM SIDE

1.5

1 (MAX) 1 (MAX)

1.55/6 H

6" MIN. THICKNESS

AASHTO #57 STONE

FACE ON UPSTREAM SIDE1.5

1 (MAX) 1 (MAX)

1.5

FLOW

MEDIAN 8" DIA.

RIP-RAP

SILT FENCE ROCK OUTLET

ELEVATION - UP-SLOPE FACE

SECTION A-A

FLAT-BOTTOM TRENCH DETAIL V-SHAPED TRENCH DETAIL

FABRIC ATTACHMENT DETAIL

SILT FENCE INSTALLATION

January, 2013

STANDARD DRAWING NO.

APPROVED BY:

GREENVILLE COUNTY STORM WATER MANAGEMENT DATE

Greenville County Storm Water Management

SURGE STONE

PERIMETER

ROAD

EXTERIOR

CHANNEL

ACCESS ROAD

2H:1V2H:1V

ACCESS

ROAD

PERIMETER

ROAD

SIDE VIEW

TOP VIEW

2H:1V2H:1V

4H:1V4H:1V

FLOW

6 - 9'Lx4.5'Wx3'H GABION

BASKETS

3 - 6'Lx4.5'Wx3'H GABION

BASKETS

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

DETAILS

21C-05.dwg

AS SHOWN 21C-05

1. ALL EROSION CONTROL MEASURES SHALL BE IN STRICT ACCORDANCE WITH LOCAL AND STATE STANDARDS - SPECIFICALLY

THE GREENVILLE COUNTY STORMWATER DESIGN MANUAL CHAPTER 8.

2. THE CONTRACTOR SHALL DILIGENTLY AND CONTINUOUSLY MAINTAIN ALL EROSION CONTROL BMPs AND STRUCTURES TO ENSURE DEVICES ARE FUNCTIONING PROPERLY TO MINIMIZE EROSION AND SEDIMENT TRANSFER. ALL EROSION AND SEDIMENT CONTROLS SHALL BE INSPECTED AT LEAST ONCE EVERY SEVEN CALENDAR DAYS, OR AFTER ANY STORM EVENT

THE PRODUCES GREATER THAN ½-INCHES OF RAINFALL DURING ANY 24-HOUR PERIOD.

3. THE TOTAL DENUDED AREA (LIMITS OF DISTURBANCE) IS APPROXIMATELY 35 ACRES.

4. THE TOTAL SITE ACREAGE IS 1140.92 ACRES. THIS WORK OCCURS IN PARCELS (PID #0580010100500 AND 0590010101300)

5. THE SOIL CLASSIFICATION IS PREDOMINANTLY: PACOLET (PdD2, PcE) AND CECIL (CeD, CIB2)

6. THE LOCATION OF EXISTING TREE PROTECTION FENCE, SILT FENCE, DIVERSION DITCHES, ETC. MAY HAVE BEEN ADJUSTED FROM LOCATIONS SHOWN IN THE DESIGN PLANS. FIELD VERIFY AND ACCOMMODATE EXISTING LOCATIONS ACCORDINGLY.

7. ADDITIONAL EROSION CONTROL DEVICES MAY BE REQUIRED DUE TO FIELD CONDITIONS, AS DIRECTED BY THE INSPECTOR, AND BASED ON CONTRACTOR SEQUENCE OF OPERATIONS.

8. ENCOMPASS STAGING AREAS AND MATERIAL STOCKPILES WITH SILT FENCE EXCEPT FOR THE POINTS OF ACCESS.

9. MAINTAIN SITE GRADING DURING CONSTRUCTION TO CONTROL RUNOFF WITH STORMWATER AND SEDIMENT CONTROL

FEATURES.

10. STABILIZATION IS THE BEST FORM OF EROSION CONTROL. PROVIDE TEMPORARY SEEDING AS NECESSARY TO ENSURE DENUDED AREAS ARE INDIVIDUALLY LESS THAN 10 ACRES AND LESS THAN 20 ACRES IN TOTAL AT ANY ONE TIME.

11. ALL PERIMETER DIKES, SWALES, DITCHES, PERIMETER SLOPES AND ALL SLOPES STEEPER THAN 3:1 SHALL BE PROVIDED TEMPORARY OR PERMANENT STABILIZATION WITH GROUND COVER AS SOON AS PRACTICABLE BUT IN ANY EVENT WITHIN 7 CALENDAR DAYS FROM THE LAST LAND-DISTURBING ACTIVITY. ALL OTHER DISTURBED AREAS SHALL BE PROVIDED TEMPORARY OR PERMANENT STABILIZATION WITH GROUND COVER AS SOON AS PRACTICABLE BUT IN ANY EVENT WITHIN 14

CALENDAR DAYS FROM THE LAST LAND-DISTURBING ACTIVITY.

12. TEMPORARY STABILIZATION MEASURES. WHERE CONSTRUCTION OR LAND DISTURBANCE ACTIVITY WILL OR HAS TEMPORARILY CEASED ON ANY PORTION OF A SITE, TEMPORARY SITE STABILIZATION MEASURES SHALL BE REQUIRED AS SOON AS

PRACTICABLE, BUT NO LATER THAN 14 CALENDAR DAYS AFTER THE ACTIVITY HAS CEASED.

13. IN ANY EVENT, SLOPES LEFT EXPOSED WILL, WITHIN 21 CALENDAR DAYS OF ANY PHASE OF GRADING, BE PLANTED OR OTHERWISE PROVIDED WITH TEMPORARY OR PERMANENT GROUND COVER, DEVICES, OR STRUCTURES SUFFICIENT TO

RESTRAIN EROSION.

14. ALL MATERIALS REQUIRED FOR CONSTRUCTION OF SEDIMENTATION AND EROSION CONTROL MEASURES SHALL BE AVAILABLE

ON SITE BEFORE ANY LAND DISTURBING ACTIVITY IS BEGUN.

15. SEDIMENT TRACKING CONTROL. STABILIZED CONSTRUCTION ENTRANCES SHALL BE LOCATED AND UTILIZED AT ALL POINTS OF INGRESS/EGRESS ON A CONSTRUCTION SITE. PREVENT THE TRANSFER OF SOIL, MUD AND DUST ONTO PUBLIC RIGHTS-OF-WAYS. REMOVE ALL MATERIALS TRACKED OR OTHERWSIE DEPOSITED ON THE PUBLIC RIGHT OF WAY.

16. CROSSINGS OF WATERWAYS DURING CONSTRUCTION IS NOT ALLOWED. DO NOT ENCROACH INTO STREAM BUFFERS, RIPARIAN

AREAS AND WETLANDS.

17. EXCAVATED SOIL SHALL BE STOCKPILED AND PRESERVED FROM EROSION OR DISPERSAL BOTH DURING AND AFTER SITE

GRADING OPERATIONS.

18. FINAL STABILIZATION OF THE SITE IS REQUIRED WITHIN 14 CALENDAR DAYS OF CONSTRUCTION COMPLETION.

19. TEMPORARY STRUCTURAL CONTROLS INSTALLED DURING CONSTRUCTION SHALL BE DESIGNED TO ACCOMPLISH MAXIMUM STABILIZATION AND CONTROL OF EROSION AND SEDIMENTATION, AND SHALL BE INSTALLED, MAINTAINED, AND REMOVED ACCORDING TO THE SPECIFICATIONS SET FORTH IN THE DESIGN MANUAL, STANDARD SPECIFICATIONS AND STANDARD DRAWINGS. ALL TEMPORARY STRUCTURAL CONTROLS SHALL BE DESIGNED TO CONTROL THE PEAK RUNOFF RESULTING FROM THE STORM EVENT IDENTIFIED IN THE DESIGN MANUAL, STANDARD SPECIFICATIONS AND STANDARD DRAWINGS.

GENERAL NOTES

NOT TO SCALE

PERIMETER ROAD3

21C-01

NOT TO SCALE

GABION BASKETS4

21C-01

NOT TO SCALE

SILT FENCE ROCK OUTLET2

21C-01NOT TO SCALE

REINFORCED SILT FENCE1

21C-01

STAKE TO

SUPPORT WIRE

SUPPORT ROPE

TO WIRE TO

PREVENT SAGGING

4'MAX

SUPPORT POST

24" INTO BOTTOM

OR SIDES

DESIGN LIFE OF FABRIC

IS 6-12 MONTHS

COIR MESH OR JUTE, TRENCHED

INTO BOTTOM AND SIDE

BAFFLE DETAIL

3'min

DESIGN NOTES:

1. USE MATTING MADE OF 700 G/M2 100% COCONUT FIBER (COIR) TWINE WOVEN INTO HIGH STRENGTH MATRIX

WITH THE PROPERTIES SHOWN IN TABLE.

2. STAPLES SHOULD BE MADE OF 0.125 INCH DIAMETER NEW STEEL WIRE FORMED INTO A ‘U’ SHAPE NOT LESS THAN 12 INCHES IN LENGTH WITH A THROAT OF 1 INCH IN WIDTH. THE STAPLES ANCHOR THE POROUS

BAFFLES INTO THE SIDES AND BOTTOM OF THE BASIN.

3. ENSURE THAT STEEL POSTS FOR POROUS BAFFLES ARE OF A SUFFICIENT HEIGHT TO SUPPORT BAFFLES AT DESIRED HEIGHT. POSTS SHOULD BE APPROXIMATELY 1-3/8” WIDE MEASURED PARALLEL TO THE FENCE, AND HAVE A MINIMUM WEIGHT OF 1.25 LB/LINEAR FT. THE POSTS MUST BE EQUIPPED WITH AN ANCHOR PLATE HAVING A MINIMUM AREA OF 14.0 SQUARE INCHES AND BE OF THE SELF-FASTENER ANGLE STEEL TYPE TO HAVE A MEANS OF RETAINING WIRE AND COIR FIBER MAT IN THE DESIRED POSITION WITHOUT

DISPLACEMENT.

4. USE 9-GAUGE HIGH TENSION WIRE FOR SUPPORT WIRE.

5. THE DESIGN LIFE OF THE FABRIC IS 6-12 MONTHS, BUT MAY NEED TO BE REPLACED MORE OFTEN IF

DAMAGED OR CLOGGED.

BAFFLE (TYP.)

INLET FLOW

EARTHEN EMBANKMENT

5' CREST WIDTH

INLET ZONE

35% OF SURFACE AREA

FIRST CHAMBER

25% OF SURFACE AREA

SECOND CHAMBER

25% OF SURFACE AREA

OUTLETINLET

PERSPECTIVE VIEW

TOP VIEW

EXTEND BAFFLES UP SIDES AS

TO NOT ALLOW FLOW AROUND

THE ENDS.

OUTLET ZONE

15% OF SURFACE

AREA

MAINTENANCE:

REPAIR/REPLACE BAFFLES WHEN THEY

COLLAPSE, TEAR OR DECOMPOSE.

REMOVE SEDIMENT WHEN CELL IS 1 / 2 FULL./

CROSS SECTIONAL VIEW

WATER LEVEL

TRASH RACK

COMPACTED EARTHEN DAM

SKIMMER

INSTALLATION NOTES:

1. CLEAR, GRUB, AND STRIP THE AREA UNDER THE EMBANKMENT OF ALL VEGETATION AND ROOT MAT. REMOVE ALL SURFACE SOIL CONTAINING HIGH AMOUNTS OF ORGANIC MATTER AND STOCKPILE OR DISPOSE OF IT PROPERLY. HAUL ALL OBJECTIONABLE MATERIAL TO THE DESIGNATED DISPOSAL AREA. PLACE TEMPORARY SEDIMENT CONTROL MEASURES BELOW BASIN AS NEEDED.

2. SELECT FILL SHALL BE USED TO CONSTRUCT THE BASIN.

3. ENSURE THAT FILL MATERIAL FOR THE EMBANKMENT IS FREE OF ROOTS, WOODY VEGETATION, ORGANIC MATTER, AND OTHER OBJECTIONABLE MATERIAL. PLACE THE FILL IN LIFTS NOT TO EXCEED 8

INCHES, AND MACHINE COMPACT IT TO 95% STANDARD PROCTOR.

4. SHAPE THE BASIN TO THE SPECIFIED DIMENSIONS. PREVENT THE SKIMMING DEVICE FROM SETTLING INTO THE MUD BY EXCAVATING A SHALLOW PIT UNDER THE SKIMMER OR PROVIDING A LOW SUPPORT

UNDER THE SKIMMER OF STONE OR TIMBER.

5. EXCAVATE A CUT-OFF TRENCH AT THE CENTERLINE OF THE EMBANKMENT FILL AREA AT A MINIMUM DEPTH AND WIDTH OF 2 FEET WITH 1:1 SIDE SLOPES. ENSURE THAT THE TRENCH IS IN UNDISTURBED

SOIL AND EXTENDS THROUGH THE LENGTH OF THE EMBANKMENT TO THE ELEVATION OF THE RISER CREST AT EACH END. THE CUT-OFF TRENCH SHOULD BE COMPACTED IN 8 INCH LIFTS TO 95%.

6. PLACE THE BARREL ON A FIRM, SMOOTH FOUNDATION OF IMPERVIOUS SOIL. DO NOT USE PERVIOUS MATERIAL SUCH AS SAND, GRAVEL, OR CRUSHED STONE AS BACKFILL AROUND THE PIPE. PLACE THE

FILL MATERIAL AROUND THE PIPE SPILLWAY IN 4-INCH LAYERS AND COMPACT IT UNDER AND AROUND THE PIPE TO AT LEAST THE SAME DENSITY AS THE ADJACENT EMBANKMENT. CARE MUST BE TAKEN NOT TO RAISE THE PIPE FROM THE FIRM CONTACT WITH ITS FOUNDATION WHEN COMPACTING UNDER THE PIPE HAUNCHES. PLACE A MINIMUM DEPTH OF 2 FEET OF COMPACTED BACKFILL OVER THE PIPE SPILLWAY BEFORE CROSSING IT WITH CONSTRUCTION EQUIPMENT. IN NO CASE SHOULD THE PIPE CONDUIT BE INSTALLED BY CUTTING A TRENCH THROUGH THE DAM AFTER THE EMBANKMENT IS

COMPLETE.

7. ASSEMBLE THE SKIMMER FOLLOWING THE MANUFACTURERS INSTRUCTIONS.

8. LAY THE ASSEMBLED SKIMMER ON THE BOTTOM OF THE BASIN WITH THE FLEXIBLE JOINT AT THE INLET OF THE BARREL PIPE. ATTACH THE FLEXIBLE JOINT TO THE BARREL PIPE AND POSITION THE

SKIMMER OVER THE EXCAVATED PIT OR SUPPORT. BE SURE TO ATTACH A ROPE TO THE SKIMMER AND ANCHOR IT TO THE SIDE OF THE BASIN. THIS WILL BE USED TO PULL THE SKIMMER TO THE SIDE

FOR MAINTENANCE.

9. EARTHEN SPILLWAYS—INSTALL THE SPILLWAY IN UNDISTURBED SOIL TO THE GREATEST EXTENT POSSIBLE. THE ACHIEVEMENT OF PLANNED ELEVATIONS, GRADE, DESIGN WIDTH, AND ENTRANCE AND EXIT CHANNEL SLOPES ARE CRITICAL TO THE SUCCESSFUL OPERATION OF THE SPILLWAY. THE SPILLWAY SHOULD BE LINED WITH RIPRAP AS INDICATED.

10. INLETS—DISCHARGE WATER INTO THE BASIN IN A MANNER TO PREVENT EROSION. USE TEMPORARY SLOPE DRAINS OR DIVERSIONS WITH OUTLET PROTECTION TO DIVERT SEDIMENT-LADEN WATER TO

THE UPPER END OF THE POOL AREA TO IMPROVE BASIN TRAP EFFICIENCY.

11. EROSION CONTROL—CONSTRUCT THE STRUCTURE SO THAT THE DISTURBED AREA IS MINIMIZED. DIVERT SURFACE WATER AWAY FROM BARE AREAS. COMPLETE THE EMBANKMENT BEFORE THE AREA IS CLEARED. STABILIZE THE EMERGENCY SPILLWAY EMBANKMENT AND ALL OTHER DISTURBED AREAS ABOVE THE CREST OF THE PRINCIPAL SPILLWAY IMMEDIATELY

AFTER CONSTRUCTION.

12. INSTALL POROUS BAFFLES AS SPECIFIED IN DETAIL.

13. AFTER ALL THE SEDIMENT-PRODUCING AREAS HAVE BEEN PERMANENTLY STABILIZED, REMOVE THE STRUCTURE AS INDICATED ON THE DRAWINGS

AND ALL THE UNSTABLE SEDIMENT. SMOOTH THE AREA TO BLEND WITH THE ADJOINING AREAS AND STABILIZE PROPERLY.

SEDIMENT BASIN ANTIFLOTATION BLOCK ANTI-SEEP COLLAR

SEDIMENT

BASIN ID

RISER

HEIGHT

(FT.)

RISER DIA.

(IN.)

BARREL DIA.

(IN.)

LENGTH

(IN.)

WIDTH

(IN.)

HEIGHT

(IN.)

NO. OF

COLLARS

COLLAR

SIZE (FT.)

COLLAR

PROJECTION

(FT.)

COLLAR

SPACING

(FT.)

1 3.75 48 36 60 60 12 2 6'X6' 3.50 25

ANTI-SEEP

COLLARS

EMERGENCY SPILLWAY

RIPRAP INLET AND OUTLET TABLE

OUTLET ID D50 (FT) APRON THICKNESS

(FT) A (IN) B (FT) L (FT) W (FT)

BASIN 1 0.50 0.75 36 9 20 23

POROUS BAFFLES

NOT TO SCALE

21C-03

NOTES:

1. 3 BAFFLES (MIN) BETWEEN INLET & OUTLET.

2. SEE N.C. DENR EROSION and SEDIMENT CONTROL

PLANNING and DESIGN MANUAL FOR CONDITIONS

WHERE PRACTICE APPLIES; PLANNING

CONSIDERATION & DESIGN CRITERIA.

OUTLET , SEE DETAIL

RIPRAP OUTLET PROTECTION

NOT TO SCALE

21C-06

END OF APRON

LAYER OF WOVEN

GEOTEXTILE FILTER FABRIC

(A) - PIPE DIAMETER (MULTIPLE

PIPES IN SOME LOCATIONS)

SEDIMENT BASIN

NOT TO SCALE

21C-03

NOTES:

1. SKIMMER WILL BE PROVIDED BY THE OWNER. CONTRACTOR TO INSTALL

PER MANUFACTURERS RECCOMENDATIONS.

RETRIEVAL

ROPE

PLAN VIEW

SIDE VIEW

PVC 90°

ELBOW (TYP.)

FLOTATION

SECTION

PVC END

CAP (TYP.)

PVC PIPE (TYP.)

HDPE FLEXIBLE DRAIN

PIPE PER MANUFACTURER

PVC TEE

SKIMMER SECTION

OVERLAPPING

CONNECTING BANDS

SKIMMER

NOT TO SCALE

21C-06

PVC VENT PIPE

CROSS SECTION OF RIPRAP

SPILLWAY AT CONTROL SECTION

PROFILE ALONG CENTERLINE

OF RIPRAP SPILLWAY

SEDIMENT

BASIN ID

MINIMUM

WIDTH (FT.)

(b)

RIPRAP LAYER

THICKNESS (IN.)

RIPRAP

D50 (IN.)

RIPRAP DMAX

(IN.)

1 20 12 8 12 b

EMERGENCY SPILLWAY

NOT TO SCALE

21C-03

LEGEND

b = BOTTOM WIDTH OF EARTH SPILLWAY AT THE CONTROL SECTION, IN FEET.

WOVEN GEOTEXTILE

4" FAIRCLOTH OR

EQUIVALENT

POND BOTTOM EL. 44

1" STEEL STRAP (TYP.)

ORIFICE PLATE

PVC TEE

RISER IS 48" DIA., 16

GAUGE CORRUGATED

METAL PIPE (CMP)

BARREL IS 36" DIA., 16 GAUGE

CORRUGATED METAL PIPE (CMP)

ANTI-FLOTATION BLOCK

(3,000 PSI CONCRETE)

CONCRETE

INFILL TO DRAIN

CUT-OFF TRENCH (2' DEEP,

2' WIDE, 1:1 SIDE SLOPES)

21C-06

RIPRAP OUTLET

PROTECTION

21C-06

10 MIN.

6"x36" ORIFICE

21C-06

CYLINDER IS 16 GAUGE

NOTE:

CORRUGATED METAL PIPE.

ISOMETRIC DETAIL

WELDED

TRASH GUARDTACK WELD

ALL AROUND

12" SPACE BAR (TYP.)

SAME MATERIAL AS

SUPPORT BAR

ACCMP RISER,

W/ 2 2/3"X1/2" CORRUGATIONS

SUPPORT BAR SIZE

#8 REBAR

OR EQUAL

8" MIN

25" TALL

72" Ø

16 GAUGE METAL

1. THE CYLINDER MUST BE FIRMLY FASTENED

TO THE TOP OF THE RISER.

2. SUPPORT BARS ARE WELDED TO THE TOP

OF THE RISER OR ATTACHED BY STRAPS

BOLTED TO THE TOP OF THE RISER.

TRASH RACK

NOT TO SCALE

21C-06

2 3 4 5 6 7 8

ISSUE DESCRIPTION

PROJECT MANAGER

PROJECT NUMBER

0 1" 2" FILENAME

SCALE

SHEET

DATE

UNIT 2 PARTIAL CLOSURE

Greenville County South Carolina10174879

P. WESTMORELAND, P.E.

0 10/2026 ISSUED FOR PROPOSALS

HDR Engineering Inc.

440 S. Church St. Suite 1200 Charlotte, NC 28202-2075 704.338.6700 of the Carolinas

PROJECT ENGINEER

DRAWN BY

SKIMMER BASIN

21C-06.dwg

AS SHOWN 21C-06

File details come from the government source that posted it. Updated Oct 26, 2026.